"I'll bet on the original," Reilly said, touting Simon Cowell and his creation before a video highlight reel touted Cowell and L.A. Reid as two of the biggest hitmakers on the planet thanks to the likes of One Direction, Justin Bieber and Il Divo.

Even without name brands for the 12-34 set, "X Factor" was the No. 1 unscripted program in the fall and the No. 1 new unscripted show for the entire season. The show jumped around the schedule and had shows of varying lengths, but Fox regularly won the nights that "X Factor" aired in its first season; the network had never won a Thursday night in the fall prior to "X Factor's" arrival.

Despite all of that, it did not come close to hitting the number of viewers that Cowell predicted - 20 million. It was the most expensive new show last year and it's likely to be among the most expensive in terms of advertising this year because of the size of its 18-49 audience, about 5.4 million viewers. It's highly likely that number will rise because of the presence of Spears and, to some degree, Lovato.

"The X Factor," "The Voice" and "American Idol" thrive financially on sponsorships and tie-ins that integrate advertisers with the shows' content. Soft drinks and cars have been key categories, but Spears and Lovato - when compared to Blake Shelton and Cee Lo Green - open a door in the youth market that otherwise might not be tapped.

Once those checks are cashed, America will learn whether Spears and Lovato have the ability to assess talent in quick and snappy ways or fall into the trap of repeating obvious, generic laudatory opinions. Chemistry among the judges, a key factor in "Idol's" developing years, will be crucial here; Cowell cannot appear to be a bully to either of the female singers, and they have to be willing to stand up to whatever criticism he delivers. The judges' personalities must be compelling to hold onto audiences.

How might they fare? Since 2007, her year of bizarre behavior, Spears has cautiously returned to the spotlight but has had a deer-in-headlights expression whenever confronted with impromptu speaking demands. Last year at MTV's Video Music Awards she was honored for her groundbreaking video work but did not speak - even when she entered the media room and posed for photographs. Her comments Monday afternoon at Fox's upfront presentation were stilted and prepared: "This is so different from everything I've ever done" was one of her four sentences.

Lovato, on the other hand, talks like a teenager: limited vocabulary and lots of slang, but also some spunkiness that Fox and the show's producers are eager to capitalize on. Saying she's "totally stoked," Lovato also noted that she intends to "represent my generation" on the show. If she's honest, she can share experiences with the younger contestants, having grown up in public in an era of social media, Disney and dance-pop. Billboard Power 100: Antonio "L.A." Reid

With two adult-targeted sitcoms and a Dick Wolf doubleheader of "Law & Order: SVU" and "Chicago Fire," NBC's Wednesday is looking for an audience separate from their Monday when "The Voice" will air prior to J.J. Abrams' "Revolution." Conversely, Fox has "Bones" and the new "Mob Doctor" to go up against "The Voice."

Thursday will be TV's big battleground, with the "X Factor" results show followed by "Glee" going up against NBC's unchanged block of comedies. ABC and CBS, which threaten Fox's domination in the 18-49 demographic with "Modern Family" and "Big Bang Theory" respectively, announce schedules next: ABC on Tuesday and CBS on Wednesday.